10 to 15 percent of adults in the United States have either impaired glucose tolerance or impaired fasting glucose (Rao S. S. et al., American Family Physician 69 (8), 1961). Impaired glucose tolerance is a pre-diabetic state of hyperglycemia that is associated with insulin resistance and increased risk of cardiovascular pathology, and which may precede type 2 diabetes mellitus (Barr E. L. et al., Circulation 116 (2): 151-7, 2007).
Type 2 diabetes is a complex polygenic disorder currently affecting the lives of over 170 million people worldwide, with that number predicted to double by 2030 [Wild S. et al., Diabetes Care 27:1047-1053, 2004]. It is characterized by insulin resistance, impaired glucose-stimulated insulin release (e.g., pancreatic β-cell dysfunction), and by inappropriate secretion of glucagon, which can be manifested as chronic hyperglycemia.